ISSN:
1432-2072
Keywords:
6-Hydroxydopamine
;
Brain Norepinephrine
;
Brain Dopamine
;
Reserpine
;
α-Methyltyrosine
;
U-14,624
;
Operant Behavior
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract The effects of prior catecholamine reductions produced by 6-hydroxydopamine on the behavioral depressant effects of catecholamine depleting and neuroleptic drugs were examined using a continuously reinforced bar-press response. In spite of large depletions, 6-hydroxydopamine treated rats showed no deficits in performance. Similarly, animals preferentially depleted of norepinephrine or dopamine showed no deficit in this task. When α-methyltyrosine or reserpine were administered at a dose which had minimal effect on responding in control animals, the 6-hydroxydopamine group in which both amines were reduced and the group preferentially depleted of dopamine showed severe deficits in bar-press responding. Responding in rats preferentially depleted of norepinephrine was slightly reduced but not to the extent observed in animals depleted of dopamine. Administration of the dopamine-Β-hydroxylase inhibitor, U-14,624, depressed responding but did not produce differential effects which correlated with brain norepinephrine concentration in the 6-hydroxydopamine-treated groups. Furthermore, the behavioral depression produced after treatment with chlorpromazine, haloperidol, and pimozide was not altered by any of the 6-hydroxydopamine treatments. These findings provide further evidence for the view that dopamine depletion plays a major role in the behavioral depressant effects of α-methyltyrosine and reserpine, but do not eliminate a role for brain norepinephrine.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00419810
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